On Tue, 2011-04-19 at 13:07 -0700, Andrew Morton wrote: > On Fri, 01 Apr 2011 14:13:12 +0200 > Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> wrote: > > > Hugh says: > > "The only significant loser, I think, would be page reclaim (when > > concurrent with truncation): could spin for a long time waiting for > > the i_mmap_mutex it expects would soon be dropped? " > > > > Counter points: > > - cpu contention makes the spin stop (need_resched()) > > - zap pages should be freeing pages at a higher rate than reclaim > > ever can > > > > I think the simplification of the truncate code is definately worth it. > > Well, we don't need to guess. These things are testable! I suppose you're right, but I'm having a bit of a hard time coming up with a sensible (reproducible) test case for the page reclaim part of this problem set. I'll try running 3 cyclic file scanners sized such that 2 exceed the memory footprint of the machine and truncate the 3rd's file after warming up. That is, unless someone has a saner idea.. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>